This relates to integrated circuits and, more particularly, to programmable integrated circuits.
Programmable integrated circuits are a type of integrated circuit that can be programmed by a user to implement a desired custom logic function. In a typical scenario, a logic designer uses computer-aided design tools to design a custom logic circuit. When the design process is complete, the computer-aided design tools generate configuration data. The configuration data is loaded into memory elements on a programmable integrated circuit to configure the device to perform the functions of the custom logic circuit. Such types of programmable integrated circuits are sometimes referred to as a field-programmable gate array (FPGA).
Operations on a conventional FPGA can often times create large current draws within a short time period, which can result in large power delivery noise that negatively impacts device performance and functionality. One way to mitigate this noise is to increase on-die decoupling capacitor. Implementing on-die capacitors increases the required die area and significantly increases cost (i.e., the amount of decoupling capacitance needed to mitigate the high current events is prohibitively large). Another way to mitigate the power delivery noise is by implementing staging, which involves dividing an operation into multiple stages, executing one stage at a time, and waiting for the current stage to finish before starting another stage. Staging helps mitigate the noise but is very time consuming.
During high current draw events on an FPGA, voltage sag may develop at the power rails. Voltage sag analysis for an FPGA design due to large current draws is more challenging than for a standard ASIC (Application-Specific Integrated Circuit) design since ASIC designs have fewer power domains and employ power gating. FPGA design on the other hand has many more power domains and lots of cross-domain signals, so the interaction among the different power rails is more complex.
It is within this context that the embodiments described herein arise.